The present invention generally relates to a novel device which aids in the accurate prediction of the effects that fabric treatments, for example, heat setting, will have upon a textile fabric. More particularly, the present invention relates to a device which can be utilized to simultaneously determine in one operation what effects will be exhibited by the textile fabric under an infinite variety of heat setting conditions, for example, the effects upon the fabric stretch, growth and shrinkages as these properties relate to varying fabric widths.
The device of the present invention generally comprises a frame which defines an interior area. The fabric material to be tested is placed on the frame and secured thereto by suitable means. At least one portion of the frame is pivotably attached to the remainder thereof so that an angular displacement can be effected to proportionally stretch the fabric yarn.
For example, in a preferred embodiment of the present invention, the frame comprises three elongated members, two of which are rigidly attached to one another to form an L-shaped side of the frame while the other member is pivotably attached to one of the L-shaped members thereby providing a "pivot arm". A turnbuckle or other suitable means is pivotably attached to the frame across the open end of the interior area defined by the L-shaped portion and the other pivotable frame member. Thus, upon operation of the turnbuckle, the pivot arm of the frame will be displaced angularly with respect to the fixed L-shaped frame member. In such a manner, proportional stretching of the fabric will occur, the fabric adjacent the turnbuckle portion being stretched more while the fabric adjacent the opposite end thereof being stretched to a lesser degree.
While in a stretched condition, the frame and fabric can be subjected to a variety of treatments, such as, heat treatments, and the fabric can thereafter be removed and examined to determined what effect varying degrees of tension have upon the fabric under the test conditions. Therefore, an accurate, and reliable laboratory prediction of the effects of heat setting conditions upon varying widths of fabric and under varying degrees of tension can be established so as to optimize production heat setting conditions in the textile mill.
According to prior practice, whenever heat setting conditions were desired to be determined and therefore, a stretch/heat setting relationship was required to be established, such determinations were accomplished on a "trial and error" basis by treating short yardages of fabric through the heat setter in production. Besides being a trial and error method, which often required many repetitions, this prior method was fairly tedious and unreliable as the short lengths and/or yardages used did not accurately represent or correlate production yardages that were treated. Accordingly, those in the art have endeavored to find suitable means for accurately and reliably predicting the effects upon fabric of heat setting conditions in a laboratory environment without resort to the trial and error basis using production equipment. It is believed that even though the need for such means was apparent, until the present invention, this need went unanswered.
There are, of course, prior art machines which can be utilized to test the physical characteristics of fabrics as exemplified by U.S. Pat. Nos. 2,568,731; 3,329,010; 3,404,576; 3,444,7288; and 3,528,145. However, such prior art devices are unsatisfactory for the particular relationships sought to be determined by utilizing the present invention, for example, the effects of heat setting upon an infinite variety of heat setting conditions and/or fabric.
For example, U.S. Pat. No. 2,568,731 discloses that a frame having two sides which are movable perpendicularly with respect to its associated, opposite fixed side can be utilized to determine stretch and recovery characteristics of the fabric. U.S. Pat. No. 3,329,010 discloses a portable device for conducting "grab tests" upon dryer-felts which may be applied to any portion of the dryer-felt while it is still upon the production machine. U.S. Pat. No. 3,400,576 and U.S. Pat. No. 3,444,728 each are concerned with determining the amount of stretch in fabric samples, while U.S. Pat. No. 3,528,145 is concerned with an apparatus for moving uniformly stretching fabrics in a cross-machine direction in order to determine when splits or cracks will occur in the fabric being stretched.
According to the present invention, however, there is provided a novel device which can be used in a laboratory environment to aid in the determination of optimum production settings for production machinery in view of the heat-setting effects upon the fabric being tested. According to the present invention, any fabric can be utilized and tested thereon, but it has been found that the present invention is particularly helpful in determining heat-setting effects upon stretchable fabrics, such as, lycra. In addition, the present invention can be utilized to predict production conditions for "bulking" fabrics having fibers which shrink in dry heat.
According to the present invention, therefore, a device is provided which is portable and can be placed in a laboratory oven to simulate production heat-setting conditions. The device according to the present invention generally comprises a frame which defines an interior area, a plurality of pins spaced along the perimeter of the frame so as to secure the textile fabric to the frame in the interior area defined thereby, and suitable means for displacing at least a portion of the frame angularly so that a portion of the fabric on the frame will be stretched to a greater degree than the fabric at another portion of the frame. Accordingly, the device according to the present invention provides a means for simultaneously simulating a variety of stretched conditions for the fabric and, subsequently, the frame having such fabric stretched thereon can be treated as desired to determine what effects such treatment will have on the fabric. Thus, since variations in the amount of tension and extension of the fabric will simultaneously be effected by utilizing the device according to the present invention, a clear and accurate understanding of the effects of various fabric treatments, such as, for example, heat-setting, can be achieved.
These and other advantages of the present invention will become more clear after careful consideration is given to the detailed discussion of the preferred exemplary embodiments thereof which follows.